SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3a266654310dc15b0cad2cb0dd1d726e5e45a81d4674f69c2c98e322aa7b2d6' 
  AND token = '0GwlD5pzaFV36Lf88/P2e9s/AXZW+B7MZe/qquKjwCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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