SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71f8427b6493daf3fcf98aac5a71171490ded56d40ebfcc6e4cc17ee14f9951a' 
  AND token = 'pNogeqAcxeNH6nb640aDl+yaA4Ftu9xTMTGiU0pIq5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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