SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32cf601407dbb5988b10c50837b2fbc4ddd12e3bbe2ced1eba5225d762abf103' 
  AND token = '7wIIbrtYK4Dz/1dMNw2xeNxo02zoVKKaXO6MPMpl/Yk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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