SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e223aec955c3e53c60911f9ac11b9c715f2c5e61e4ddbc2c7382e84b0fdb3d26' 
  AND token = 'oRxysmR5j5AWRwYHcfyRmQmXbxNvHikG2QZxrA794C4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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