SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd78490d47d72d2ca6efb10803361e42784557152785eb47fd7b08ac6214ca941' 
  AND token = 'gKB/Dz0Cv/mYvkqU98CzFnbkUx/rzx7Z0DOK8KwXqfc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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