SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b96a01f0e372857715999964072824c55dc9cfd1c1185cb26a2be10971af7e4' 
  AND token = 'VlUiBiM19sjEAeh9cazP16hsn2Uj3mMBpVlXNYucoOI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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