SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ed99f99ab020b26766744d1bd89686e692cb37217914e19d291c875c314b0d4' 
  AND token = 'I9GNBfFxoj+TkKKqlLwLFC5tP66zbyuc/DjtYQWE/lg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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