SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '556ae9fa788bd5da5753ee514e32eb660dfad9f64da54574eef34a81ce20903b' 
  AND token = 'n5vS1gFpb7nLQJIvEuS4+tr5mYpy7Nt2A30guuCpYzI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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