SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7afa7c11d75d03ddb22162b89e976de5e5edf82681cd0f550c4bbde75dc56d6' 
  AND token = 'If7khUNloJCSDByd7KkLIG9xH5cNVHMwUXKZFkMpLTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}