SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3f5130f5b10cb2340fec835abcc2b84227349683c6b83429b3555caa4a87884' 
  AND token = 'EjurIT99W3QJIVNLjyL4qM0YbJr+ENJa/3WFjCQZlc4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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