SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f1e1763610434cc86b09901de38a89bff0c9e464c461ee4a2d69d5b8199469c' 
  AND token = 'FpVmI0+jEArLsBM5diPuJMTlZSfpEa9IU8bNwmAk8uo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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