SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1bf0c1a084c5bf6a406e045de758e4aad37ca28273c2b535c6e3151585469f2' 
  AND token = 'X+tP1H3sPW92AKxIMrR8mklDktfZyo6QVYkVGDFZOik=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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