SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f94101cf481d27138270725d7b00271fc33499e24d591a9062f2bc5f05f30548' 
  AND token = 'go1ezXoZhUKfMAFWLaXDbkQcDVePJ45BDV2mgc67k30=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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