SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34dc86cb05c53bec47aa63296428daf2ba33cc5277ddaa5b8ed07c06978d117f' 
  AND token = 'W/NSKWB53BqQvqIBtZyw9axiMbwMHhi3X6GkxQlF0aI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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