SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0bcf8e7f75c1ea94c8d8d5d3317f5aba8432ff3369e3a012a2d49b273277279' 
  AND token = 'ABU/5JSh7rwel23c9ILenOP3mW/dHH+LMtaVRVwqjUA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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