SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74230d11d298c10f0b3c337408106caedc61e594bf96f47d94cb87eaef621767' 
  AND token = 'akfLkXF6JbwDmvMYgobov3Cng/ZyXXfEAng4b1UGreY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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