SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef18bf86ed0e479ee631140219e1e748fe2489dd6e4f670d2ea299a5353574f9' 
  AND token = 'R+Gv0YvMZESXhow5JUF2gXQ/ZVKBANSjpzeaVzvKi08=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}