SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41d6170d83441ca78c494309a3ba2a84866694e49932a2327c9cc57bb0991165' 
  AND token = 'rppSDO8BoxtPGTh1Q/uNybhiXp6vRFdVegoVIS85ohg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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