SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a484f8d3846ecc9a32401345d129324aea3e552d4d6e9041f9f8dd4b2aad7a6b' 
  AND token = 'tYCUgQYzqv1Bn6zWbrSBFVYFd831AilimXgRuOJVFCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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