SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cc4f7b46ce6f4dba54f81c5411725866813b7f16f623543457819154b52007e' 
  AND token = 'j3QC42pkTLTHCbhpRLdzK5pAhPgGsX4gdqX1drZd/nU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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