SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a5f22d90773fbd80a17c96a1024539ec4d734c975f19b2e7d000b75c60c0ae6' 
  AND token = '6hWjtmnQvrA9GruttJBHH0RpTKLLNH8gY6wISZhPiXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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