SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93de906f1f4558e3ac717215c78b4e275b183f16ee3cd6e4dd56c3940f1876bd' 
  AND token = 'CXMXXvNU/kaoJGUzDXsEGT+3x6XCIWYw5lfLeFq8FKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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