SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2abf58588d3739d075b4ea227eb01a1ad9c1721e96d54409c1863bbb0b087b63' 
  AND token = 'OOT2pJvaxvkP2ARFJJc+/yOcDSYjrjkOFp2MAJ4TUeo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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