SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6880f2f0e18170bf999c31f6e9c08f4d10974c12764760f1cdef062eeaaae4b' 
  AND token = 'bOJ0FSPVKxw5gswAMaorLecwEqgw6tCzp7tNrcs4PJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}